Transcriptional regulation of the cydDC operon, encoding a heterodimeric ABC transporter required for assembly of cytochromes c and bd in Escherichia coli K-12: regulation by oxygen and alternative electron acceptors

J Bacteriol. 1997 Oct;179(20):6525-30. doi: 10.1128/jb.179.20.6525-6530.1997.


The expression of the cydDC operon was investigated by using a chromosomal phi(cydD-lacZ) transcriptional fusion and primer extension analysis. A single transcriptional start site was found for cydD located 68 bp upstream of the translational start site, and Northern blot analysis confirmed that cydDC is transcribed as a polycistronic message independently of the upstream gene trxB. cydDC was highly expressed under aerobic growth conditions and during anaerobic growth with alternative electron acceptors. Aerobic expression was independent of ArcA and Fnr, but induction of cydDC by nitrate and nitrite was dependent on NarL and Fnr.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • ATP-Binding Cassette Transporters / genetics*
  • Aerobiosis
  • Amino Acid Sequence
  • Anaerobiosis
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism
  • Base Sequence
  • Carrier Proteins*
  • Cytochrome b Group
  • Cytochrome c Group / biosynthesis*
  • Cytochromes / biosynthesis*
  • DNA-Binding Proteins / metabolism
  • Electron Transport Chain Complex Proteins*
  • Escherichia coli / genetics*
  • Escherichia coli / metabolism
  • Escherichia coli Proteins*
  • Gene Expression Regulation, Bacterial
  • Iron-Sulfur Proteins / metabolism
  • Molecular Sequence Data
  • Nitrates / metabolism
  • Nitrites / metabolism
  • Operon*
  • Oxidoreductases / biosynthesis*
  • Peptidylprolyl Isomerase*
  • Recombinant Fusion Proteins / biosynthesis
  • Transcription, Genetic*


  • ATP-Binding Cassette Transporters
  • Bacterial Proteins
  • Carrier Proteins
  • CydC protein, E coli
  • CydD protein, E coli
  • Cytochrome b Group
  • Cytochrome c Group
  • Cytochromes
  • DNA-Binding Proteins
  • Electron Transport Chain Complex Proteins
  • Escherichia coli Proteins
  • FNR protein, E coli
  • Iron-Sulfur Proteins
  • Nitrates
  • Nitrites
  • Recombinant Fusion Proteins
  • NarL protein, E coli
  • Oxidoreductases
  • cytochrome bd terminal oxidase complex, E coli
  • SurA protein, E coli
  • periplasmic peptidylprolyl cis-trans isomerase
  • Peptidylprolyl Isomerase